Pwyll and a few of his knights enjoyed a lazy day resting upon a fairy hill listening to the songs from Mother Nature playing throughout the countryside. The music was suddenly interrupted by the sound of hooves approaching. Pwyll saw the most wondrous woman riding sidesaddle upon a shining white horse. Her golden cape was flowing with the wind. She clenched a magical bag in her hand. Pwyll commanded one of his men to ride out and see who this woman was who rode just out of reach. His proudest knight jumped on his steed and rode as swiftly as he could. She raced far ahead, and then vanished.

The next day Pwyll gathered two of his finest horsemen to sit on the mound as he had done the day before. Once again the lady appeared riding toward him just close enough for his senses to be awakened. He requested the two horsemen to greet her, but before they could, she turned her horse and rode away. No matter how fast the horsemen rode, she rode faster out of their reach.

On the third day Pwyll went to the mound by himself. Sitting upon his horse he waited, wishing to see the beautiful woman on the white horse. Soon, the enchanting woman appeared. Pwyll commanded his horse to rush toward her, and once again, she rode ahead of him staying in sight yet still out of reach. In desperation Pwyll cried out for her to stop. Her white horse dug his hooves into the soft dirt feeling the pull of the reins. Turning to look at Pwyll's eyes, she replied, "You only need to ask." and introduced herself as Rhiannon, daughter of Hefaidd, the Old. The two spent the day together riding the hills, racing through the countryside, sharing stories.

Rhiannon told Pwyll she had traveled to the fairy mound for it was him she wanted to spend her life with. Pwyll was enchanted by her independence and beauty. Together they agreed to belong to each other. He promised that in a year and one day he would return and claim her as his bride. Time passed and Pwyll returned and spoke to Hefaiid, the King, requesting Rhiannon's hand. The king, knowing of the Great Prince, told him it would be an honor and gave Pwyll Rhiannon's hand in marriage.

A great feast was put forth. During the celebration a beggar entered the castle. Walking to the head table he was blinded by the shine around Rhiannon. He stood beside Pwyll and requested a wish from the Prince. Enjoying the festivities he told the beggar he would grant him his want and asked what shall it be. Lifting his head, removing the illusion, he told the two, "I am Gwawl, son of Clud, and I want Rhiannon for my bride."

Horrified, Pwyll could not, would not, allow Rhiannon to leave his side. Rhiannon calmly spoke to Pwyll. She told him that to retain his title of an honorable man, he must agree. She then kissed his cheek and told him that she had promised once to Pwyll and she will again, never to belong to another.

A year and a day passed and Gwawl and Rhiannon were seated at the head of the table appearing to be as one. Meanwhile, Pwyll was waiting outside the castle gate dressed as a peasant carrying a large bag, and clear instructions on how to regain her hand. As the music played throughout the halls, Pwyll entered as Gwawl had done, and requested a wish. Before Gwawl would answer, he wanted to know the man's desire. Opening the bag, Pwyll asked to have the bag filled to the rim with food. To Gwawl the peasant's request seemed reasonable so he commanded the bag be filled. The festivities were coming to a close and the bag was still half empty. Pwyll explained to Gwawl that the bag could never be filled unless royal blood tramped on the food inside. Rhiannon encouraged Gwawl to do as he was told. Gwawl, wanting to please, stepped inside only to begin falling into darkness. Pwyll quickly tied the bag. He told Gwawl he would only be freed when he agreed to release Rhiannon and seek no revenge. Gwawl agreed. Pwyll and Rhiannon were united and returned to Dyfed to rule.